Re: Implementation

From: Jacques M Mallah <>
Date: Mon, 26 Jul 1999 20:44:39 -0400

        I finally got to read Maudlin's full paper.
        I was surprised that, since he makes the argument that he does,
that he was aware that (and emphasizes) that information transmission does
not require any physical activity. (A lack of being sent a 1 means a 0.)
In fact this is the whole basis for his argument: for him consciousness
must require more activity than is needed for information transmission. I
fail to see how he could hold such a point of view. A computer processes

On Sun, 25 Jul 1999 wrote:
> Let me offer an alternative approach to the Maudlin/Marchal implementation
> question which is consistent with computationalism but avoids some of
> the difficulties.
> Computationalism says that implementation of a certain class of algorithms
> is necessary and sufficient for consciousness. Maudlin presents an
> experiment where a seemingly minor and (he argues) irrelevant change makes
> the difference between whether a conscious computation is implemented
> or not.
> However to conclude that Maudlin's change (adding an inert block) makes
> consciousness go away (even assuming computationalism) is a fallacy.
> We agree that the initial computation (sans block) is conscious.
> We agree that adding the block changes the computation (by changing
> counterfactual behavior). But we cannot conclude from this that the
> resulting computation is not conscious.
> The new configuration, with the block, implements a different computation
> than without (if you take counterfactuals into consideration). But have
> we proven that this new computation is not conscious? No! All we have
> proven is that this is different from the computation we started with.
> But more than one computation can be conscious, obviously. It is
> conceivable that the new computation, although different, is conscious
> as well. This is a possible escape from Maudlin's argument.

        I agree with this objection to Maudlin as well.
        Assume that the device implements the following computation: If
the initial state of the Turing-like machine is X, or if it is any state
which a Turing machine would pass through if started in state X, then the
computer will enter the next state in that series; otherwise it will halt.
        With the floats (blocked add-on machines can be added but are
irrelevant, the floats can just pull a string) it would seem that
Maudlin's machine can implement such a computation.
        Such a computation can still be very nontrivial. As a simple
example X can be a program to calculate pi. I would think that if a
Turing machine started with program X would be conscious, then such a
modified program would also be.
        The objection will now be raised that, as Maudlin thinks, the
physical system he describes is too simple to be conscious. This is not
neccessarily true. A Turing machine is not that complicated to begin
with. For example, after the spout passes a trough, if (((it was already
full) and (there was no empting trigger)) or (the spout was unblocked))
then (the trough will be full) else (it will not be). The fact is there
are logic gates all over the place, at least in that view of it.
        And unlike Chalmers' clock and dial, Maudlin's example certainly
raises no threat of panpsychism. His device is quite complicated and
unlikely to exist in nature. It is also clear that the device has encoded
in it a lot of information about the computation.
        Bruno, I think it is now abundently clear that Maudlin's paper
does not rule out physical computationalism, and other people on the list
have seen that as well.

        What about the 'movie' angle? Would a device that replayed a
given series of states implement a computation? For example, suppose
there is a two dimensional grid on which are layed out the values (0 or 1)
of each bit that would be encountered in the computation as a function of
position (x) and time step (t). Now take a long bar, parrallell to x, and
send it across the grid at constant velocity. Define the state of the
system to be the sequence of bits under the bar.
        Obviously it would be a problem if such a system implemented the
computation. The bar plays almost no role so one would have little choice
but to say it is irrelevant, thus that a static picture could be conscious
(rejecting computationalism).
        Adding a third dimension one could even have one such sheet for
every possible initial condition of the machine, stacked on top of each
        Fortunately this is rather different from Maudlin's example and it
does not compute except in the clock and dial sense, according to my
        BTW I have realized for unrelated reasons that my proposal needs
modification. I will work on it when I am able.

                         - - - - - - -
              Jacques Mallah (
       Graduate Student / Many Worlder / Devil's Advocate
"I know what no one else knows" - 'Runaway Train', Soul Asylum
            My URL:
Received on Mon Jul 26 1999 - 17:57:54 PDT

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